It was science fiction before, but now it's really happening, Young Skywalker: The US Navy and Air Force are going to install liquid-cooled, solid-state lasers in combat airplanes. Laser turrets designed to defend the planes by shooting incoming threats like surface-to-air missiles and rockets. Seriously. The above is an official concept image by DARPA, but integration is happening this year, with real firing tests coming in 2014.
The USAF has been playing with lasers in planes for a while. They worked to create the the highly successful—but ultimately shelved—Boeing YAL-1 Airborne Laser Testbed. Remember Reagan's Star Wars? This was one of the few technologies that we got to work outside those 3D animations that scared the Soviets so much.